Hydraulic cylinder apparatus

ABSTRACT

A hydraulic cylinder apparatus for a hydraulic press effectively provides in itself the hydraulically movable platen of the press. A hollow hydraulic cylinder body which is open at one end and closed at the other has a cylinder of large diameter at the open end and a cylinder of small diameter at the closed end communicating with the cylinder of large diameter substantially midway between the ends of the cylinder body. A piston body is longitudinally movably received in the cylinder body and it has intermediate its ends a piston of large diameter in the large diameter cylinder, a piston extension of small diameter in the small diameter cylinder and a ram extension of intermediate diameter extending through the open end of the cylinder body and effectively providing the hydraulically movable platen of the hydraulic press. Hydraulic packing is carried by the piston of large diameter and engages the cylinder of large diameter for hydraulically sealing the piston body in the cylinder body. Guide means is provided between the cylinder of small diameter and the piston extension for guiding longitudinal movement of this end of the piston body, and guide means is provided between the cylinder of large diameter and the ram extension for guiding longitudinal movement of this end of the piston body.

United States Patent [72! Inventors Tnmlo Otsulu "mo: Eugene E. Granltowskl. Chicago, both 01, Ill. (21] Appl. No. 832,195 [22] Filed June 11.1969 [45] Patented July 13, 1971 [73] Assignee Veraou Allsteel Press Company ChlcagoJll.

[$4] HYDRAULIC CYLINDER APPARATUS 10 Claims. 6 Drawing Figs.

[52] U.S,Cl 100/269, 92/165, 92/l66 {51] Int. Cl. 8301i 1/32 [50] Field of Search IOU/214, 269; 72l453;83/639; 92/105 165 PR,166

[56] llelerencu Cited UNITED STATES PATENTS 817,38l 4/1906 Matson 92/l65 X 996,693 7/1911 Webb 100/269 X 2,550,601 4/1951 Rosenberg.................... 92/165 X FOREIGN PATENT 656.579 2/1938 Germany 100/269 Primary Examiner-Billy J. Wilhite Altomey-Wallenstein, Spangenberg, Hattis & Strampel ABSTRACT: A hydraulic cylinder apparatus for a hydraulic press effectively provides in itself the hydraulically movable platen of the press. A hollow hydraulic cylinder body which is open at one end and closed at the other has a cylinder of large diameter at the open end and a cylinder of small diameter at the closed end communicating with the cylinder of large diameter substantially midway between the ends of the cylinder body. A piston body is longitudinally movably received in the cylinder body and it has intermediate its ends a piston of large diameter in the large diameter cylinder, a piston extension of small diameter in the small diameter cylinder and a ram extension of intermediate diameter extending through the open end of the cylinder body and effectively providing the hydraulically movable platen of the hydraulic press. Hydraulic packing is carried by the piston of large diameter and engages the cylinder of large diameter for hydraulically sealing the piston body in the cylinder body. Guide means is provided between the cylinder of small diameter and the piston extension for guiding longitudinal move ment of this end of the piston body, and guide means is provided between the cylinder of large diameter and the ram extension for guiding longitudinal movement of this end of the piston body.

ln li l PATENTEUJULIMQII 3,592,131

sum 1 OF 3 j uruo Otsula @mzamwa HYDRAULIC CYLINDER APPARATUS Conventional hydraulic presses have a separate platen attached to one or more hydraulic pistons for movement thereby. Gib ways are provided on the columns of the press to guide movement of the platen accurately in the direction of movement thereof by the piston or pistons. This movement may be either vertical, horizontal or at some angle with respect to either the vertical or horizontal planes. Platens are also guided on posts of presses with round post type columns.

The principal object of this invention is to provide a hydraulic cylinder apparatus for a hydraulic press which effectively provides in itself the hydraulically movable platen of the press so that the need for separate platens and guides therefor, such as gib ways, posts or the like, is eliminated.

Briefly, in accordance with this invention, the hydraulic cylinder apparatus includes a hollow cylinder body which is open at one end and closed at the other and which has a cylinder of large diameter at the open end and a cylinder of small diameter at the closed end communicating with the cylinder of large diameter substantially midway between the ends of the cylinder body. A piston body is longitudinally movably received in the cylinder body and it has intermediate its ends a piston of large diameter in the large diameter cylinder, a piston extension of small diameter in the cylinder of small diameter and a ram extension of intermediate diameter extending through the open end of the cylinder body. Guide means is provided between the cylinder of small diameter and the piston extension for guiding longitudinal movement of this end of the piston body, and guide means is provided between the cylinder of large diameter and the ram extension for guiding longitudinal movement of this end of the piston body. With both ends of the piston so guided, the ram extension effectively provides in itself the hydraulically movable platen of the hydraulic press without the need for a separate platen and additional guides therefor.

The guide means for the ram extension of the piston body preferably includes a plurality of circumferentially spaced rollers radially adjustably carried by the cylinder body for engaging the ram extension in such manner that the rollers may be preloaded for zero clearance. The guide means for the piston extension may also include adjustable rollers or may be a bearing bushing or the like, the choice being dependent upon the degree of accuracy required in guiding. This method of guiding provides much greater accuracy and less deflection of the ram extension or platen when subjected to oil center loading. A key and keyway are preferably utilized for preventing rotation of the piston body with respect to the cylinder body and the piston of large diameter is preferably provided with hydraulic packing to hydraulically seal the piston body in the cylinder body.

The hydraulic cylinder apparatus of this invention may be utilized in substantially any press construction, and the direction of its movement may be in substantially any direction as expressed above. The hydraulic cylinder may be in the crown member or the bed member of the press and the latter arrangement is set forth herein by way of illustration.

Further objects of this invention reside in the details of construction of the hydraulic cylinder apparatus. in the cooperative relationships between the component parts thereof and in the relation thereof with respect to the press structure.

Other objects and advantages of this invention will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawings in which:

FIG. 1 is a front elevational view of a press structure incorporating the hydraulic cylinder apparatus of this invention;

FIG. 2 is a side elevational view of the press structure looking from the right of FIG. 1;

FIG. 3 is a horizontal sectional view through the press structure taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is an enlarged vertical sectional view of the hydraulic cylinder apparatus of this invention and also diagrammatically illustrating portions of the press structure, FIG. 4 being taken substantially along the line 4-4 of FIG. 2;

FIG. 5 is a further enlarged horizontal view of a portion of the hydraulic cylinder apparatus, it being an enlargement of a portion of the apparatus illustrated in FIG. 3; and

FIG. 6 is a vertical sectional view taken substantially along the line 6-6 of FIG. 5.

A press structure generally designated at 10 is diagrammatically illustrated in FIGS. 1, 2 and 3. While the press structure may taken various forms, it is shown herein by way of illustration as to include a supporting base 11 suitably secured to a foundation 12. A bed member 13 is suitably secured to the supporting base II and a plurality of columns l4 extend upwardly from the bed member 13 to support a crown member 15, the crown member 15 having a suitable downwardly facing stationary platen 16. The press structure may be prestressed by means of threaded tie rods 17 extending through the bed member 13, the columns 14 and the crown member 15 upon which tie rod nuts 18 and 19 are screw threadedly mounted for prestressing purposes. The foregoing press structure as diagrammatically illustrated in FIGS. 1 to 3 is conventional and a further description thereof is not considered necessary.

The bed member 13 is in the form ofa hydraulic cylinder body which is open at the top and closed at the bottom, which has a cylinder 22 of large diameter at the open end and which has a cylinder 23 of small diameter at the closed end communicating with the cylinder 22 of large diameter substantially midway between the ends of the cylinder body. A piston body 24 is longitudinally movably received in the cylinder body or bed member 13 and intermediate its end it has a piston 25 of large diameter which is received in the large diameter cylinder 22. The piston body also includes a piston extension 26 of small diameter which is received in the small diameter cylinder 23 and a ram extension 27 of intermediate diameter which extends through the open end of the cylinder body 13, the ram extension 27 providing the hydraulically movable platen of the hydraulic press structure 10. The piston 25 is provided with annular hydraulic packing 28 which is held in place by a shouldered bushing 29 engaging a shoulder on the piston 25 and a shouldered bushing 30 having an upwardly facing shoulder. A retainer ring 31 is secured by screws 32 to the piston 25, the retainer ring 31 engaging the shoulder on the bushing 32 for securing the bushings 29 and 30 and the hydraulic packing 28 in place on the piston 25. In this way the piston body 24 is hydraulically sealed in the cylinder body 13.

The ram projection 27 of the piston body 24 is guided for longitudinal movement by a plurality of circumferentially spaced rollers as is shown more clearly in FIGS. 3 to 6. For purposes of illustration herein (FIG. 3) eight such guide rollers are illustrated. About the cylinder 22 of large diameter the cylinder body I3 is provided with a plurality of notches 33 upon which are located a plurality of brackets 34. Each bracket 34 includes a downwardly extending leg extending into the cylinder 22 of large diameter which is provided with a cam surface 35 and side flanges 36 extending therealong. A roller support 37 for each bracket 34 has a downwardly extending extension having a cam surface 38 engaging the cam surface 35 on the bracket 34, the roller support 37 being guided in the bracket 34 by the flanges 36. The roller support 37 is bifurcated as indicated at 39 for receiving the guide roller.

A pin 41 having a head 42 extends through the bifurcated end of the roiler support 37 and it has a reduced threaded portion 43 for receiving a nut 43A for securing the pin 41 in place in the roller support 37. The roller support 37 is preferably in the form of a roller bearing having an inner race 44 carried by the pin 4|, a plurality of rollers 45 and an outer race 46 forming the roller which guides the ram extension 27 of the piston body 24. The rollers are sealed by end plates 47 carried by the inner race 44. When the nut 43A is tightened on to the pin 41, the head 42 of the pin 41 operates to clamp the plates 47 and the inner race 44 against the roller support 37 for fixedly mounting the inner race 44 and allowing free rotation of the outer race 46 forming the roller.

The roller support 37 is vertically adjustable with respect to the bracket 34 and the amount of vertical adjustment is determined by a shim 48, the bracket 34, the roller support 37 and the shim 48 being secured in place on the cylinder body 13 by screws 49. Upward and downward positioning of the roller support 37 as determined by the thickness of the shim 48 causes radial adjustment of the roller 46 with respect to the ram extension 27 of the piston body 24. By appropriate grinding the thickness of the shim 48 may be adjusted so as to cause the roller 46 to engage the ram extension 27 with a desired amount of preloading. When all of the rollers 46 are thus appropriately radially adjusted with the desired amount of preloading, zero clearance for the guiding of the ram extension 27 of the piston body 24 is provided, and since the rollers 46 are in the form of roller bearings, there is minimum resistance to the longitudinal movement of the ram extension 27 even though it is guided with zero clearance. Preferably the ram extension 27 is provided with a plurality of flat inserts 50 so as to provide flat surfaces against which the rollers 46 roll as the ram extension 27 is moved upwardly and downwardly. These flat surfaces provide a sound base for preloading the rollers 46 as expressed above and also have the tendency of preventing rotation of the piston body 24 with respect to the cylinder body 13. The rollers 46 may be made cylindrical or they may be provided with a convex curvature as illustrated A bracket 52 is secured by screws 53 to the cylinder body 13, the bracket 52 carrying a bar 54 having a key 55 received in a keyway 56 formed in the ram extension 27 of the piston body 24. The key 55 and the keyway 56 operate to prevent rotation of the piston body with respect to the cylinder body as the piston body is longitudinally moved in the accurately guided manner discussed above.

If desired, the piston extension 26 of the piston body 24 may be similarly guided by rollers although it may be guided by a bushing 58 carried by the piston extension 26 and closely engaging the cylinder 23 of the cylinder body l3. Whether rollers or the bushing 58 are utilized is dependent upon the degree of guiding accuracy desired.

From the foregoing it is seen that the piston body 24 is accurately guided at its ends in its longitudinal movement in the cylinder body l3, the piston body 24 being raised by hydraulic pressure supplied below the piston 25 and being lowered by its own weight as the hydraulic pressure permits. As a result, the ram extension 27 at the upper end of the piston body 24 can of itself form the hydraulically movable platen of the press so that the need for separate platens and guide means for such separate platens is eliminated. The ram extension 27 itself may form the platen or a platen may be rigidly secured thereto by means of bolts or the like.

By way of example only, the cylinder 22 of large diameter may comprise a 7 l 86 inch diameter bore and the cylinder 23 of small diameter may comprise a 25% inch diameter bore, and the piston body 24 may be 95 inches long, with the piston 25 being 13 inches long and the ram extension 27 being 47 inches long. The ram extension may have a diameter of 50 inches and the piston body 24 may have a stroke of inches with a shut height of 54 inches. The rollers 46 may have a diameter of 7 inches, they being heavy duty rollers having a maximum static capacity of 28,860 pounds and a basic dynamic capacity of 75,380 pounds to provide maximum guiding accuracy with zero clearance with hydraulic pressures in the range of 80 tons or so.

While for purposes of illustration one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and, therefore, this invention is to be limited only by the scope of the appended claims.

We claim:

1. A hydraulic cylinder apparatus for a hydraulic press which also effectively provides the hydraulically movable platen of the press comprising, a hollow hydraulic cylinder body open at one end and closed at the other end and having a cylinder of large diameter at the open end and a cylinder of small diameter at the closed end communicating with the cylinder of large diameter substantially midway between the ends of the cylinder body, a piston body longitudinally movably received in the cylinder body and having intermediate its ends a piston of large diameter in the large diameter cylinder. a piston extension of small diameter extending toward the closed end of the cylinder body in the small diameter cylinder, and a ram extension of intermediate diameter extending through the open end of the cylinder body and effectively providing the hydraulically movable platen of the hydraulic press, hydraulic packing carried by the piston of large diameter and engaging the cylinder of large diameter for hydraulically sealing the piston body in the cylinder body, guide means between the cylinder of small diameter and the piston extension for guiding longitudinal movement of this end of the piston body, and guide means between the cylinder of large diameter and the ram extension for guiding longitudinal movement of this end of the piston body.

2. The hydraulic cylinder apparatus as defined in claim I including a keyway longitudinally arranged in the piston body and a key carried by the cylinder body engaging in said keyway to prevent rotation of the piston body with respect to the cylinder body.

3. The hydraulic cylinder apparatus as defined in claim 1 wherein at least one of said guide means includes a plurality of circumferentially spaced rollers radially adjustably carried by the cylinder body and engaging the associated extension of the piston body.

4. The hydraulic cylinder apparatus as defined in claim 1 wherein said guide means between the cylinder of large diameter and the ram extension includes a plurality of circumlerentially spaced rollers radially adjustably carried by the cylinder body between the cylinder of large diameter and the ram extension and engaging the ram extension.

5. A hydraulic cylinder apparatus as defined in claim 4 including a shouldered bushing on the piston of large diameter on one side of the hydraulic packing with the shoulder thereof engaging a shoulder on the piston, a shouldered bushing on the piston of large diameter on the other side of the hydraulic packing with the shoulder thereof facing the ram extension, and a retainer ring about the ram extension secured to the piston of large diameter and engaging the shoulder on the last mentioned shouldered bushing for retaining the bushings and the hydraulic packing in place on the piston of large diameter.

6. A hydraulic cylinder apparatus as defined in claim 4 wherein said guide means between the cylinder of small diameter and the piston extension includes a bushing carried by the piston extension and engaging the cylinder of small diameter.

7. The hydraulic cylinder apparatus as defined in claim 1 wherein said guide means between the cylinder of large diameter and the ram extension includes a plurality of circumferentially spaced brackets carried by the cylinder body and having cam members extending into the cylinder of large diameter, a plurality of roller supports having cam members extending into the cylinder and engaging the cam members of the brackets, means for adjustably positioning the roller supports on the brackets to cause the cam members to adjustably radially position the roller supports, and a plurality of rollers carried by the roller supports between the cylinder of large diameter and the ram extension and engaging the ram exten- S10.

8. A hydraulic cylinder apparatus as defined in claim 7 wherein said guide means between the cylinder of small diameter and the piston extension includes a bushing carried by the piston extension and engaging the cylinder of small diameter.

9. A hydraulic cylinder apparatus as defined in claim 7 including a shouldered bushing on the piston of large diameter on one side of the hydraulic packing with the shoulder thereof engaging a shoulder on the pis on, a shouldered bushing on the piston of large diameter on the other side of the hydraulic packing with the shoulder thereof facing the ram extension, and a retainer ring about the ram extension secured to the piston of large diameter and engaging the shoulder on the last mentioned shouldered bushing for retaining the bushings and the hydraulic packing in place on the piston of large diameter.

10. A hydraulic cylinder apparatus as defined in claim I ineluding a shouldered bushing on the piston of large diameter on one side of the hydraulic packing with the shoulder thereof engaging a shoulder on the piston, a shouldered bushing on 

1. A hydraulic cylinder apparatus for a hydraulic press which also effectively provides the hydraulically movable platen of the press comprising, a hollow hydraulic cylinder body open at one end and closed at the other end and having a cylinder of large diameter at the open end and a cylinder of small diameter at the closed end communicating with the cylinder of large diameter substantially midway between the ends of the cylinder body, a piston body longitudinally movably received in the cylinder body and having intermediate its ends a piston of large diameter in the large diameter cylinder, a piston extension of small diameter extending toward the closed end of the cylinder body in the small diameter cylinder, and a ram extension of intermediate diameter extending through the open end of the cylinder body and effectively providing the hydraulically movable platen of the hydraulic press, hydraulic packing carried by the piston of large diameter and engaging the cylinder of large diameter for hydraulically sealing the piston body in the cylinder body, guide means between the cylinder of small diameter and the piston extension for guiding longitudinal movement of this end of the piston body, and guide means between the cylinder of large diameter and the ram extension for guiding longitudinal movement of this end of the piston body.
 2. The hydraulic cylinder apparatus as defined in claim 1 including a keyway longitudinally arranged in the piston body and a key carried by the cylinder body engaging in said keyway to prevent rotation of the piston body with respect tO the cylinder body.
 3. The hydraulic cylinder apparatus as defined in claim 1 wherein at least one of said guide means includes a plurality of circumferentially spaced rollers radially adjustably carried by the cylinder body and engaging the associated extension of the piston body.
 4. The hydraulic cylinder apparatus as defined in claim 1 wherein said guide means between the cylinder of large diameter and the ram extension includes a plurality of circumferentially spaced rollers radially adjustably carried by the cylinder body between the cylinder of large diameter and the ram extension and engaging the ram extension.
 5. A hydraulic cylinder apparatus as defined in claim 4 including a shouldered bushing on the piston of large diameter on one side of the hydraulic packing with the shoulder thereof engaging a shoulder on the piston, a shouldered bushing on the piston of large diameter on the other side of the hydraulic packing with the shoulder thereof facing the ram extension, and a retainer ring about the ram extension secured to the piston of large diameter and engaging the shoulder on the last mentioned shouldered bushing for retaining the bushings and the hydraulic packing in place on the piston of large diameter.
 6. A hydraulic cylinder apparatus as defined in claim 4 wherein said guide means between the cylinder of small diameter and the piston extension includes a bushing carried by the piston extension and engaging the cylinder of small diameter.
 7. The hydraulic cylinder apparatus as defined in claim 1 wherein said guide means between the cylinder of large diameter and the ram extension includes a plurality of circumferentially spaced brackets carried by the cylinder body and having cam members extending into the cylinder of large diameter, a plurality of roller supports having cam members extending into the cylinder and engaging the cam members of the brackets, means for adjustably positioning the roller supports on the brackets to cause the cam members to adjustably radially position the roller supports, and a plurality of rollers carried by the roller supports between the cylinder of large diameter and the ram extension and engaging the ram extension.
 8. A hydraulic cylinder apparatus as defined in claim 7 wherein said guide means between the cylinder of small diameter and the piston extension includes a bushing carried by the piston extension and engaging the cylinder of small diameter.
 9. A hydraulic cylinder apparatus as defined in claim 7 including a shouldered bushing on the piston of large diameter on one side of the hydraulic packing with the shoulder thereof engaging a shoulder on the piston, a shouldered bushing on the piston of large diameter on the other side of the hydraulic packing with the shoulder thereof facing the ram extension, and a retainer ring about the ram extension secured to the piston of large diameter and engaging the shoulder on the last mentioned shouldered bushing for retaining the bushings and the hydraulic packing in place on the piston of large diameter.
 10. A hydraulic cylinder apparatus as defined in claim 1 including a shouldered bushing on the piston of large diameter on one side of the hydraulic packing with the shoulder thereof engaging a shoulder on the piston, a shouldered bushing on the piston of large diameter on the other side of the hydraulic packing with the shoulder thereof facing the ram extension, and a retainer ring about the ram extension secured to the piston of large diameter and engaging the shoulder on the last mentioned shouldered bushing for retaining the bushings and the hydraulic packing in place on the piston of large diameter. 